Method for manipulating an adjustable shape guide catheter

ABSTRACT

A method of manipulating a catheter assembly involves providing an inner catheter member movably disposed within an outer catheter member. At least a distal end portion of the inner catheter member has a stiffness greater than that of at least a distal end portion of the outer catheter member. The distal end portion of the outer catheter member includes a deflectable distal end. The method further involves advancing the inner catheter member through the outer catheter member toward the deflectable distal end of the outer catheter member, and longitudinally displacing the distal end portion of the inner catheter member relative to the deflectable distal end of the outer catheter member to alter a shape of the deflectable distal end.

RELATED PATENT DOCUMENTS

This is a divisional of U.S. patent application Ser. No. 09/876,876,filed on Jun. 7, 2001, to which Applicant claims priority under 35U.S.C. §120, and which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to catheters. More particularly,it pertains to catheters having an adjustable shape for manipulationinto complex locations, such as the coronary sinus ostium.

BACKGROUND

Current cardiac treatments employing the use of catheters are dependentupon complexity of the location to be treated, unless surgery isemployed to access complex locations. The physician has had to choosebetween placing the catheter and treating a site in a place of greatestinterest or areas which are anatomically accessible with catheters.Prior catheter placement has been generally restricted to areas whichcan be repeatedly accessed by the physician. One approach to expand theareas in which a catheter can be placed includes the use of steerablecatheters. One type of steerable catheter offers maneuverability tospecific, otherwise inaccessible sites by providing catheters shapedspecifically to access a particular site. This type of catheter islimited as it cannot be used to reach locations requiring activearticulation during placement.

Other types of steerable catheters provide catheters having deflectingtips, which include a pullwire attached to the distal tip portion of thecatheter. During use of this type of catheter, the wire is pulledcausing the tip to defect. Alternatively, the wire is restrained whilethe catheter is advanced, allowing the distal tip to deflect. However,one drawback is that the tip of the catheter is deflected only in aprescribed manner. While the tip can be altered during the placement ofthe catheter, the steerable tip has a radius of curvature which isfixed, thus restricting the accessibility of the distal tip to certainanatomical sites. This results in a limit to the complexity of the sitein which the catheter can be positioned.

Another drawback is that an inventory of different sized catheters isnecessary, where each catheter has a differently sized radius ofcurvature. In addition, it is occasionally not known what size of radiusis appropriate prior to the procedure. When it is discovered, after thecatheter has been positioned, that the radius of the catheter isincorrect, the catheter must be completely withdrawn from the patient,and a new properly radiused catheter tip must be reintroduced into theheart. This substitution can cause additional trauma to the patient, andis costly since it adds time to the procedure. In addition, theinitially selected but improperly sized catheter must then be discarded,never having been used for its intended purpose. This adds moreunnecessary cost since the catheters are typically single use itemswhich are discarded after a single use.

Accordingly, what is needed is a catheter which is adjustable, and whichcan be positioned within complex locations of a body and is able toaccommodate a variety of anatomical variations. What is further neededis a catheter having a shape which is modifiable during a procedure.

SUMMARY

The present invention is directed to methods of manipulating a catheterassembly. According to one embodiment, a method of manipulating acatheter assembly involves providing an inner catheter member movablydisposed within an outer catheter member. At least a distal end portionof the inner catheter member has a stiffness greater than that of atleast a distal end portion of the outer catheter member. The distal endportion of the outer catheter member includes a deflectable distal end.The method further involves advancing the inner catheter member throughthe outer catheter member toward the deflectable distal end of the outercatheter member, and longitudinally displacing the distal end portion ofthe inner catheter member relative to the deflectable distal end of theouter catheter member to alter a shape of the deflectable distal end.

In accordance with another embodiment, a method of manipulating acatheter assembly involves providing an inner catheter member movablydisposed within an outer catheter member. At least a distal end portionof the inner catheter member has a stiffness greater than that of atleast a distal end portion of the outer catheter member. The distal endportion of the outer catheter member includes a deflectable distal end.The method further involves advancing the inner catheter member throughthe outer catheter member toward the deflectable distal end of the outercatheter member, longitudinally displacing the distal end portion of theinner catheter member relative to the deflectable distal end of theouter catheter member to alter a shape of the deflectable distal end,and rotating the distal end portion of inner catheter member relative tothe deflectable distal end of the outer catheter member in response to atorqueing force applied to a proximal end of the inner catheter member.

A catheter assembly according to another embodiment has an outercatheter member which extends from a first distal end to a firstproximal end, where the first distal end is flexible. The outer cathetermember includes a first lumen therein, where the first lumen extendsfrom the first distal end to the first proximal end. An inner cathetermember is movably disposed within the first lumen of the outer cathetermember. The inner catheter member extends from a second distal end to asecond proximal end.

Options which can be included with that above are as follows. Forinstance, a braid of material is disposed within a wall of the outercatheter member and/or the inner catheter member, or between the outerand inner catheter members. In addition, the outer catheter member isdefined in part by a first length from the first distal end to the firstproximal end, the braid defined in part by a second length, and thesecond length of the braid is less than the first length. Anotherexample of an option includes having the first distal end of the outercatheter member including two or more segments of material, such as afirst segment and a second segment, and the first segment comprises adifferent material than the second segment.

A further option is where the first distal end of the outer cathetermember includes two or more segments of material, including a firstsegment and a second segment, and the first segment has a differentdurometer than the second segment. Yet another option includes the outercatheter member having a preformed curve proximate to the first distalend. Optionally the inner catheter member has a preformed curveproximate to the second distal end. Another option is where the outercatheter member is more flexible than the inner catheter member. Afurther embodiment includes a handle adapted to slide the inner cathetermember relative to the outer catheter member.

In another embodiment, a catheter assembly has an outer catheter memberwhich extends from a first distal end to a first proximal end, where thefirst distal end is flexible. The outer catheter member includes a firstlumen therein, where the first lumen extends from the first distal endto the first proximal end. An inner catheter member is movably disposedwithin the first lumen of the outer catheter member. The inner cathetermember extends from a second distal end to a second proximal end. Thecatheter assembly includes a handle assembly having an outer handlemember and an inner handle member, where the inner handle member isslidably received within the outer handle member. The outer cathetermember is coupled with the first proximal end of the outer handlemember, and the inner catheter member is coupled with the secondproximal end of the inner handle member.

Options which can be included with that above are as follows. Forinstance,

one option includes the outer handle member having a cut out therein,and the inner handle member has a projection, where the projection isslidingly disposed through the cut out. Another option is where theouter catheter member is more flexible than the inner catheter member.Another example of an option includes having the first distal end of theouter catheter member including two or more segments of material, suchas a first segment and a second segment, and the first segment comprisesa different material than the second segment.

A further option is where the first distal end of the outer cathetermember includes two or more segments of material, including a firstsegment and a second segment, and the first segment has a differentdurometer than the second segment. Yet another option includes the outercatheter member having a preformed curve proximate to the first distalend. Optionally the inner catheter member has a preformed curveproximate to the second distal end. In another option, a braid ofmaterial is disposed within a wall of the outer catheter member and/orthe inner catheter member, or between the outer and inner cathetermembers. Yet another option includes a luer hub adapted to secure theouter catheter member with the outer handle member. In yet anotheroption, the assembly further includes a sprocket having sprocket teethwhich are movably coupled with the outer handle member. In addition, theinner handle member includes inner member teeth which are engaged whichthe sprocket teeth of the outer handle member.

A catheter assembly has an outer catheter member which extends from afirst distal end to a first proximal end. The outer catheter memberincludes a first lumen therein, where the first lumen extends from thefirst distal end to the first proximal end. An inner catheter member ismovably disposed within the first lumen of the outer catheter member.The inner catheter member extends from a second distal end to a secondproximal end, where the inner catheter member has a second lumentherein. The second lumen of the inner catheter member extends from thesecond distal end to the second proximal end. In addition, a means forflexing the first distal end of the outer catheter member is included.Options include those discussed above.

A method includes disposing an inner catheter member within an outercatheter member, where the outer catheter member extends from a firstdistal end to a first proximal end, and the first distal end isflexible. The outer catheter member has a first lumen, and the innercatheter member has a second lumen therein. The method further includesinserting the outer catheter member and the inner catheter member withina body, moving the inner catheter member relative to the outer cathetermember, and flexing the first distal end of the outer catheter member.

Options for the method are as follows. The method optionally furtherincludes disposing fluid and/or a medical device through the secondlumen of the inner catheter member. A further option includes removingthe inner catheter member. Yet another option includes disposing fluidand/or a medical device through the first lumen of the outer cathetermember before or after the inner catheter has been removed. In addition,optionally torque is applied to the inner catheter member. A furtheroption includes sliding the inner catheter member within the outercatheter member.

The catheter assembly is easily manipulatable by the physician intocomplex shapes, which allows for the assembly to be positioned intocomplex areas within a patient, for instance, within the coronary sinusostium. Since the catheter assembly is able to be positioned within manydifferent areas, regardless of their complexity in shape, a physicianhas more available options when treating a patient. A further benefit ofthe catheter assembly is that the device is easy to use, easy tomanufacture, and provides a cost benefit in both assembly and in itsuse.

These and other embodiments, aspects, advantages, and features of thepresent invention will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the art byreference to the following description of the invention and referenceddrawings or by practice of the invention. The aspects, advantages, andfeatures of the invention are realized and attained by means of theinstrumentalities, procedures, and combinations particularly pointed outin the appended claims and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view illustrating a catheter assemblyconstructed in accordance with one embodiment.

FIG. 2 is a cross sectional view illustrating a catheter assemblyconstructed in accordance with one embodiment.

FIG. 3 is a cross sectional view illustrating a catheter assemblyconstructed in accordance with one embodiment.

FIG. 4 is a cross sectional view illustrating a catheter assemblyconstructed in accordance with one embodiment.

FIG. 5 is a cross sectional view illustrating a catheter assemblyconstructed in accordance with one embodiment.

FIG. 6 is a cross sectional view illustrating a catheter assemblyconstructed in accordance with another embodiment.

FIG. 7 is a side elevational view illustrating a catheter assemblyconstructed in accordance with one embodiment.

FIG. 8 is a side elevational view illustrating an outer handle member ofa catheter assembly constructed in accordance with one embodiment.

FIG. 9 is a cross sectional view illustrating an outer handle member ofa catheter assembly constructed in accordance with one embodiment.

FIG. 10 is a side elevational view illustrating an inner handle memberof a catheter assembly constructed in accordance with one embodiment.

FIG. 11 is a side elevational view illustrating an inner handle memberof a catheter assembly constructed in accordance with one embodiment.

FIG. 12 is a side elevational view illustrating an outer handle memberof a catheter assembly constructed in accordance with one embodiment.

FIG. 13 is a cross sectional view illustrating an outer handle member ofa catheter assembly constructed in accordance with one embodiment.

FIG. 14 is a side elevational view illustrating a catheter assemblyconstructed in accordance with one embodiment.

FIG. 15 is a view illustrating a catheter assembly constructed inaccordance with one embodiment.

DESCRIPTION OF THE EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which is shown byway of illustration specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that structuralchanges may be made without departing from the scope of the presentinvention. Therefore, the following detailed description is not to betaken in a limiting sense, and the scope of the present invention isdefined by the appended claims and their equivalents.

A catheter having an adjustable shape is provided. The adjustablecatheter is used for cannulating complex locations within a body, forinstance, within the coronary sinus ostium for the purpose of acutedeployment of drugs or acute and chronic deployment of medicalinstrumentation or devices such as a pacing lead.

FIG. 1 illustrates a catheter assembly 100 constructed in accordancewith one embodiment. The catheter assembly generally includes an outercatheter member 110 and an inner catheter member 120 which is movablyreceived by the outer catheter member 110. The outer catheter member 110extends from a first distal end 112 to a first proximal end 114, and hasa first lumen 116 therein, as shown in FIGS. 2 and 3. The first lumen116 extends from the first distal end 112 to the first proximal end 114of the outer catheter member 110. The first distal end 112 of the outercatheter member 110 is flexible. Optionally, the entire outer cathetermember 110 is more flexible than the inner catheter member 120. In oneembodiment, the first distal end 112 of the outer catheter member 110has a preformed curve 118 therein.

The first lumen 116 of the outer catheter member 110 receives thereinthe inner catheter member 120. The inner catheter member 120 extendsfrom a second distal end 122 to a first proximal end 124, and optionallyhas a second lumen 126 therein, as shown in FIGS. 2 and 3. The secondlumen 126 extends from the second distal end 122 to the second proximalend 124 of the inner catheter member 120. In another option, the innercatheter member 120 does not have a lumen, such as an electrodecatheter. The user optionally can open the hemostasis mechanism,discussed further below, and extend the electrode catheter out of theouter catheter member to use the electrodes thereon to sense and/or pacetissue.

In one option, the inner catheter member 120 has a preformed curve 128therein. The preformed curve 128 of the inner catheter member 120 isprovided in addition to the preformed curve 118 of the outer cathetermember 110. Alternatively, the preformed curve 128 of the inner cathetermember 120 is provided in alternative to the preformed curve 118 of theouter catheter member 110.

FIGS. 4-6 illustrate other options for the catheter assembly 100. In oneoption, the catheter assembly 100 includes a braid 130 of material,where the braid 130 is disposed between the outer catheter member 110and the inner catheter member 120, as shown in FIG. 4. Optionally, thebraid 130 of material is secured to the inner catheter member 120 or theouter catheter member 110, for example by providing the braid 130 ofmaterial within the wall construction of the inner and/or outer cathetermember. It should be noted that providing the braid 130 of materialwithin the wall construction also includes, but is not limited to,forming the braid in the center of the wall, the outer portion of thewall, or the inner portion of the wall of the inner or outer cathetermember. In yet another option, the inner catheter member 120 isreleasably attached to the inner handle, using a luer style hub. Thebraid 130 of material includes a braid 130 of stainless steel material,although sleeves of other types of materials would be suitable as well,such as flat or round wire, rigid polymeric material such as PTFE,polyurethane, or polyesters. In one embodiment, the braid 130 ofmaterial has a length which is less than that of the outer cathetermember 110, as shown in FIG. 5.

FIG. 6 illustrates another embodiment of the catheter assembly 100,where the first distal end 112 of the outer catheter member 110 includestwo or more segments 108 of material. The two or more segments include,but are not limited to, a first segment 104 and a second segment 106. Inone option, the first segment 104 is comprised of a different materialthan the second segment 106. In another option, the first segment 104 iscomprised of a material having a different durometer than the materialof the second segment 106.

FIG. 7 illustrates another embodiment of a catheter assembly 200. Thecatheter assembly 200 includes the outer catheter member 110 and theinner catheter member 120, and the variations thereto, as discussedabove in reference to FIGS. 1-6. In addition, the catheter assembly 200includes a handle assembly 250 which is adapted to move the innercatheter member 120 relative to the outer catheter member 110.

The handle assembly 250 includes an outer handle member 260 and an innerhandle member 280. The inner handle member 280 is slidably received bythe outer handle member 260. The outer handle member 260, as shown inmore detail in FIGS. 8 and 9, has a first passage 262 for receiving theinner handle member 280 therein. The first passage 262 extends from adistal end 266 to a proximal end 264 of the outer handle member 260, andallows for fluids and/or instrumentation to be disposed therethrough.The outer handle member 260 further includes a cut out 268 therein,which optionally, extends only partially from the distal end 266 to theproximal end 264. The cut out 268, as shown in cross-section in FIG. 9,is adapted to receive therethrough a portion of the inner handle member280, as discussed further below. Referring again to FIG. 7, the outerhandle member 260 is coupled with the outer catheter member 110, and isoptionally coupled with a luer style hub 261.

The inner handle member 280 is shown in more detail in FIG. 10. Theinner handle member 280 includes an inner passage 282 therein. The innerpassage 282 extends from a distal end 286 to a proximal end 284 of theinner handle member 280, and allows for fluids and/or instrumentation tobe disposed therethrough. The inner handle member 280 further includes aprojection 288. The projection 288 is optionally integral with the innerhandle member 280. Alternatively, the projection 288 is a separatecomponent which is coupled with the inner handle member 280.

The inner handle member 280 is coupled with the inner catheter member120, in one embodiment, with an adjustable grommet and hub mechanism,for instance, a hemostasis-like mechanism 290. The hemostasis-likemechanism 290 allows for different inner catheter members to beinterchanged within the catheter assembly 200. For instance, innercatheter members having differing amounts of stiffness and/or varyingshapes can be used to achieve further complex movements through thevasculature.

As a user advances the projection 288 which is slidingly received in thecut out 268, for example, by using a thumb, the inner catheter member120 is moved within the outer catheter member 110, thereby altering thedistal end 112 of the outer catheter member 110. As the distal end 112of the outer catheter member 110 is modified, a change results in thecurve of the distal end 112 to modify the geometry and the position ofthe catheter assembly 200.

FIGS. 11-13 illustrate another embodiment of the catheter assembly 100′.Similar to the previously discussed embodiment, the handle assembly 250includes an outer handle member 260 and an inner handle member 280. Theinner handle member 280 is slidably received by the outer handle member260. The outer handle member 260, as shown in more detail in FIGS. 12and 13 has a first passage 262 for receiving the inner handle member 280therein. The first passage 262 extends from a distal end 266 to aproximal end 264 of the outer handle member 260, and allows for fluidsand/or instrumentation to be disposed therethrough.

The outer handle member 260 further includes a sprocket 294 movablycoupled with the outer handle member 260. For instance, in one option,the sprocket 294 is rotatably coupled with the outer handle member 260.The sprocket 294 includes a lever 292 which allows for the sprocket tobe rotated along 296. It should be noted that the lever 292 is usable toimplement other motions of movement, such as linear movement. Thesprocket 294 further includes sprocket teeth 278, which are configuredto engage with a portion of the inner handle member 280, as furtherdiscussed below.

The inner handle member 280 is shown in more detail in FIG. 11. Theinner handle member 280 includes an inner passage 282 therein. The innerpassage 282 extends from a distal end 286 to a proximal end 284 of theinner handle member 280, and allows for fluids and/or instrumentation tobe disposed therethrough. The inner handle member 280 further includesinner member teeth 270 projecting from a surface of the inner handlemember 280. The inner member teeth 270 are configured to engage thesprocket teeth 278. As a user manipulates the sprocket 294, for exampleby using the lever 292, the inner handle member 280 is moved relative tothe outer handle member 260. As the sprocket teeth 278 engage the innermember teeth 270, the inner catheter member 120 (FIG. 7) is moved withinthe outer catheter member 110 (FIG. 7), thereby altering the distal end112 (FIG. 1) of the outer catheter member 110 (FIG. 7). As the distalend 112 (FIG. 1) of the outer catheter member 110 (FIG. 7) is modified,a change results in the curve of the distal end 112 (FIG. 1) to modifythe geometry and the position of the catheter assembly 200 (FIG. 7). Thesprocket 294 and the lever 292 facilitates single-handed manipulation ofthe instrument, freeing the physicians other hand for other types ofcatheter manipulation or for manipulation of other medical instruments.

During use of the catheter assembly, a method includes disposing aninner catheter member within an outer catheter member, to form one ofthe several catheter assemblies discussed above, where the outercatheter member extends from a first distal end to a first proximal end,and the first distal end is flexible. As mentioned above, the outercatheter member has a first lumen, and the inner catheter member has asecond lumen. The inner catheter member is disposed within the firstlumen of the outer catheter member.

The method further includes inserting the outer catheter member and theinner catheter member within a body, for instance, of a human patient.The inner catheter member is moved relative to the outer cathetermember, for instance, by sliding the inner catheter member within theouter catheter member. Optionally, as discussed above, a handle assemblyis used to slide the inner catheter member relative to the outercatheter member. The first distal end of the outer catheter member, inone option, is flexed in a two dimensional motion as shown in FIG. 14along “A.” In another option, as shown in FIG. 15, the first distal endof the outer catheter member is flexed in a three dimensional motion,for example, by rotating the shaped inner catheter member. Flexing ofthe outer catheter member allows positioning of the catheter assemblywithin complex locations of a patient.

Once the catheter assembly is positioned within the body, or at leastpartially positioned within the body, fluid and/or a medical device isdisposed through the second lumen of the inner catheter member. Themedical device, for example, comprises a cardiac lead or alternatively,a guidewire. The fluid includes, but is not limited to, saline ormedicine, or radiopaque dye. Optionally, the inner catheter member isremoved from the catheter assembly, and fluid and/or a medical device isdisposed through the first lumen of the outer catheter member. Theimplanting physician or technician has more options since the variouslumens accommodate various types and sizes of medical instruments, orrates of introduction of fluids. In yet a further option, torque isapplied to the inner catheter member, which is particularly beneficial,for instance, when the inner catheter is shaped in conjunction with theouter catheter. Applying torque to the inner catheter having a preformedshape provides a three-dimensional geometry at the tip. In yet anotheroption, a stiff guide wire, either straight or preformed, is advanceddown the central lumen of the inner catheter, which allows foradditional shape control.

Advantageously, the catheter assembly is easily manipulatable by themedical technician into complex shapes, which allows for the assembly tobe positioned in to complex areas within a patient, for instance, withinthe coronary sinus ostium. Since the catheter assembly is able to bepositioned within many different areas, regardless of their complexityin shape, a medical technician or physician has more available optionswhen treating a patient. A further benefit of the catheter assembly isthat the device is easy to use, easy to manufacture, and provides a costbenefit in both assembly and in its use.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. It should be noted that embodiments discussed indifferent portions of the description or referred to in differentdrawings can be combined to form additional embodiments of the presentinvention. The scope of the invention should, therefore, be determinedwith reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

1. A method of manipulating a catheter assembly, the method comprising:providing an inner catheter member movably disposed within an outercatheter member, at least a distal end portion of the inner cathetermember having a stiffness greater than that of at least a distal endportion of the outer catheter member, the distal end portion of theouter catheter member having a deflectable distal end; advancing theinner catheter member through the outer catheter member toward thedeflectable distal end of the outer catheter member; and longitudinallydisplacing the distal end portion of the inner catheter member relativeto the deflectable distal end of the outer catheter member to alter ashape of the deflectable distal end.
 2. The method of claim 1, whereinadvancing the inner catheter member comprises slidably advancing theinner catheter member through the outer catheter member.
 3. The methodof claim 1, wherein advancing the inner catheter member comprisesrotatably advancing the inner catheter member through the outer cathetermember.
 4. The method of claim 1, wherein at least one of advancing andlongitudinally displacing is performable using single-handedmanipulation at a proximal end of the catheter assembly.
 5. The methodof claim 1, wherein each of advancing and longitudinally displacing isperformable using single-handed manipulation at a proximal end of thecatheter assembly.
 6. The method of claim 1, wherein each of advancingand longitudinally displacing is contemporaneously performable usingsingle-handed manipulation at a proximal end of the catheter assembly.7. The method of claim 1, further comprising advancing a guide memberthrough the inner catheter and relative to the deflectable distal end ofthe outer catheter member to further alter the shape of the deflectabledistal end.
 8. The method of claim 1, wherein the distal end portion ofthe inner catheter member comprises a preformed curve.
 9. The method ofclaim 1, wherein the distal end portion of the outer catheter membercomprises a preformed curve.
 10. The method of claim 1, wherein thedistal end portions of the inner and outer catheter members respectivelycomprise a preformed curve.
 11. A method of manipulating a catheterassembly, the method comprising: providing an inner catheter membermovably disposed within an outer catheter member, at least a distal endportion of the inner catheter member having a stiffness greater thanthat of at least a distal end portion of the outer catheter member, thedistal end portion of the outer catheter member having a deflectabledistal end; advancing the inner catheter member through the outercatheter member toward the deflectable distal end of the outer cathetermember; and longitudinally displacing the distal end portion of theinner catheter member relative to the deflectable distal end of theouter catheter member to alter a shape of the deflectable distal end;and rotating the distal end portion of inner catheter member relative tothe deflectable distal end of the outer catheter member in response to atorqueing force applied to a proximal end of the inner catheter member.12. The method of claim 11, wherein advancing the inner catheter membercomprises slidably advancing the inner catheter member through the outercatheter member.
 13. The method of claim 11, wherein advancing the innercatheter member comprises rotatably advancing the inner catheter memberthrough the outer catheter member.
 14. The method of claim 11, whereinat least two of advancing, longitudinally displacing, and rotating areperformable using single-handed manipulation at a proximal end of thecatheter assembly.
 15. The method of claim 11, wherein advancing,longitudinally displacing, and rotating are performable usingsingle-handed manipulation at a proximal end of the catheter assembly.16. The method of claim 11, wherein at least two of advancing,longitudinally displacing, and rotating are contemporaneouslyperformable using single-handed manipulation at a proximal end of thecatheter assembly.
 17. The method of claim 11, wherein at least one oflongitudinally displacing and rotating the distal end portion of theinner catheter member relative to the deflectable distal end of theouter catheter member facilitates alteration of the shape of thedeflectable distal end in two dimensions.
 18. The method of claim 11,wherein longitudinally displacing and rotating the distal end portion ofthe inner catheter member relative to the deflectable distal end of theouter catheter member facilitates alteration of the shape of thedeflectable distal end in three dimensions.
 19. The method of claim 11,further comprising advancing a guide member through the inner catheterand relative to the deflectable distal end of the outer catheter memberto further alter the shape of the deflectable distal end.
 20. The methodof claim 11, wherein one or both of the distal end portion of the innercatheter member and the distal end portion of the outer catheter membercomprises a preformed curve.